This invention relates to a method and apparatus for picking up laminations from a stack, for instance, laminations for use in manufacturing stators or rotors of a dynamo electrical machine. More particularly, the invention relates to a method and apparatus for packeting stator and rotor laminations for electric motors.
In addition to methods for the pressureless packeting of laminations according to, e.g., the German patent disclosures 29 49 230 and 31 47 034, whereby a specific number of laminations is picked up only under the dead weight of the stack, it has previously been known, for instance from the German patent disclosures 20 19 924 and 29 07 261, to mount a stack of laminations between clamping plates, in order to achieve greater accuracy of the packet height, and to mark off a specific packet height by means of a blade which, with reference to one of the clamping plates, is run sideways against the stack at a specific point. To avoid variations resulting from laminations which are not uniformly thick across their circumference, it is already known in the prior art to first pick up laminations of one-half packet height, rotate this half lamination packet by 180.degree., recombine it with the stack and only then to pick up the entire lamination packet. The clamping plate of the prior art design, which together with the blade delimits the lamination packet to be picked up from the stack, is provided for that purpose on its backside, with two different stop faces which correspond to the respective half and whole packet heights and which in the two angular positions of the clamping plate which are offset by 180.degree., are rotated together with the first packet half, individually make contact with a specific support surface of the packeting head which picks up the lamination packet and moves the packet away from the stack.
The packeting performed with this prior art device has the disadvantage that even with a minimal adjustment of the spacing of the clamping surface of one clamping plate relative to the blade, which may become necessary during the manufacture of a packet series of a specific height, due to the added thickness variations of the processed laminations, production must be interrupted for correcting the splitting plane of the blade. Such an interruption of production has so far been necessary also when changing over from one packet height to another for exchange of the clamping plate. Besides the time lost and the necessity of operating with a number of clamping plates with different stop faces, the further consequence resulted heretofore that in the simultaneous manufacture of several different packet heights several packeting devices also needed to be linked with an insulating device for inserting long insulation strips of different lengths in the stator or rotor slots, although the insulating devices have, in the case of a large number of slots, a much longer cycle time than the packeting devices. Therefore, the problem underlying the invention is to improve the prior packeting method and the device for its application so that adjustments and changes of packet height can be made without or with only very short interruptions of production.
The above problem is solved by the method and apparatus according to the present invention as disclosed and claimed hereinafter.